This invention relates, in general, to fluid heater apparatus and, more particularly, to fluid heater apparatus which provide a heated wash fluid to a cleanable surface, and, still more specifically, to a heated wash fluid for a vehicle windshield wash system.
It is necessary in many diverse applications to quickly elevate the temperature of a fluid to a higher use temperature. For example, it is desirable to be able to provide instant hot water, for use in homes, offices and campers, as well as for industrial processes.
In cleaning applications, it is known that hot fluid removes dirt and other debris from a surface much better and much faster than colder fluids. One heated fluid application is a vehicle wash fluid system, such as a windshield wash system as well as vehicle wash systems applied to camera lenses, exterior lamps and lamp lenses, mirrors, etc. Vehicles are typically provided with at least one and usually multiple windshield washers which are used to clear the field of vision in a windshield or rear backlight.
Typically, a nozzle or spray device is provided adjacent to or as part of the windshield wiper to disperse a pattern of wash fluid onto the windshield prior to and during the wiping operation to improve the efficiency of the wiping operation so as to provide a clear field of vision for the driver or vehicle passengers. The wash fluid is typically stored in a reservoir in the engine compartment and is pumped through the spray device upon manual activation of a control actuator by the vehicle driver.
Since it is known that warm or heated fluid provides better cleaning efficiency than cold fluid, it is known to provide a heated wash fluid to a vehicle window spray device. Various wash fluid heating devices have been developed, but all typically utilize a heat exchanger design wherein a heat source is disposed in a body through which the wash fluid flows. The wash fluid picks up heat source in the heat exchange body to elevate its temperature prior to dispersion through the spray nozzle onto a vehicle window.
However, such prior wash fluid heating devices are inefficient in terms of heat transfer capability as well as being able to only provide a small quantity or a short duration of heated wash fluid onto a vehicle window. Further, direct contact of the fluid with the heat source causes hot spots in the fluid and lower temperature fluid portions which do not contact the heat source.
Thus, it would be desirable to provide a fluid heater apparatus which provides a heated fluid in an efficient manner, which has a minimal power requirements, and, which is capable of providing near instantaneous heated wash fluid and larger quantities of heated wash fluid for a longer spray application of the heated fluid onto a cleanable surface than previously devised wash fluid heater devices.
The present invention is a heater apparatus ideally suited for heating fluid.
The heater apparatus includes a thermally conductive mass having a plurality of throughbores extending through first and second ends. Heater means are mounted in the thermally conductive mass concentrically within and surrounded by the plurality of throughbores, the heater means supplying heat, when activated, to the thermally conductive mass. An inlet fluidically coupled to one end of each of the plurality of throughbores and an outlet fluidically coupled to each of the other end of the throughbores define parallel flow paths between the inlets and the outlets through the plurality of throughbores wherein fluid flowing through the throughbores absorbs heat from the thermally conductive mass.
In one aspect, each of the plurality of throughbores has a helical path between opposed ends.
In another aspect, the throughbores have identical flow cross-section areas.
In one aspect, the throughbores are arranged in first and second concentric, circumferentially spaced inner and outer rings about the thermally conductive mass. The maximum cross-sectional dimension of the bores in the inner ring is less than the maximum cross-sectional dimension of the throughbores in the outer ring.
In another aspect, the thermally conductive mass is formed of a plurality of lamina, each lamina carrying the throughbores and apertures for receiving the heater element(s) therethrough.
Certain lamina are rotatably offset from adjacent lamina by an offset distance to create a stepwise helical advance in the throughbore through the stack of lamina between the first and second ends of the stack.
The present heater apparatus is also usable in non-vehicle and non-cleaning fluid applications. For example, the present heater apparatus can be easily adapted for use in providing elevated, high temperature fluids for home, office and camper use as well as for industrial processes.
In one aspect, a plurality of lamina are coaxially aligned and rotatably offset from a like number of lamina which are coaxially aligned with other.
In summary, there has been disclosed a fluid heater apparatus module apparatus which can be variably adjusted to provide different fluid discharge temperatures as needed for different applications. Despite the variable fluid discharge temperatures which may be necessary for each different application, the overall construction of the heater apparatus is substantially identical thereby minimizing manufacturing costs, assembly and part multiplication.